1. Field of the Invention:
This invention relates to heat barrier apparatus, and, more particularly, to radiant barriers for reflecting long wave radiation to prevent the transfer of unwanted heat.
2. Description of the Prior Art:
In contemporary usage, there are different types of insulation used to prevent the transfer of heat. In home construction, there are typically several different types of insulation used, including fiber batts, which are used in both attic and wall applications. Also included are loose fill blown insulation, which is typically ground cardboard or the like treated with borax or other fire retardants, or other types of treated particulate insulation, which are blown into attics. Similar types of insulation are also blown or inserted into the interior of brick or block walls. Sheet rock, or wall board (Gypsum) insulation is used on walls and on ceilings, with foil backed sheet rock typically used on exterior walls. Foam sheeting is typically also used on exterior walls beneath the outer facing or surface of the walls.
Insulation is generally referred to in terms of R-values, with the higher the R-value the greater the resistance to the transfer of heat. It is only the foil layer on foil-back insulation that is designed for reflecting radiant energy. Wallboard, or gypsum board, used for exterior walls generally includes a foil layer facing outwardly, toward the outside of the building, for reflecting radiant energy which penetrates the walls. Fiberglass batts may also include a foil layer for reflecting radiant energy. The other types of insulation discussed above are generally simply barriers having relatively low thermal conductivity and which accordingly simply act as retardants for the transfer of heat. However, once the heat is transferred, the same layers act as insulation for retaining the heat.
Heat, such as from the sun, is typically in the form of long wave radiation. As radiation, the radiant energy may appropriately be reflected by reflective surfaces. However, when the surfaces reflect the radiant energy, other surfaces may reflect the radiant energy back. When the radiant energy is going in different directions, it is obvious that different types of energy reflectors may be of substantial help in preventing radiant energy from penetrating where it is not wanted.
The apparatus of the present invention provides different surfaces for reflecting radiant energy. The reflective elements come in two different types, one for loose fill applications and second for layered applications. The radiant barrier apparatus of the present invention achieves a substantially increased efficiency in reflecting the long wave radiation due to the redundancy in the reflecting surfaces.